Tire sidewalls have labels. Here, “labels” encompass company names, company logos, color designations, information data, identification codes, hatching and the like.
The labels of the tire sidewall should exhibit high manufacturing quality, should provide an impression of high quality of the tire, and should visually highlight the tire in relation to other tires. This is achieved for example through the application of (coloured) foils to the tire sidewall. The foils have the labels.
As materials of the foils, which are also referred to as “rubber labels”, use is made for example of elastomers, thermoplastic elastomers, thermoplastics or combinations of the abovementioned materials. The punched elastomer foils with imprinted plastics surface are of outstanding importance.
From U.S. Pat. No. 7,232,498, it is known for the tire sidewall to be equipped with rubber labels which are formed by a rubber foil which is approximately 1 mm in thickness and which is vulcanized onto the sidewall of the tire. The foil thickness range normally lies between 0.1 and 1.5 mm. The rubber labels are pressed under the action of pressure and heat onto the tire for labelling, and cure or vulcanize onto the tire. The rubber labels generally bear colored, printed-on text, figures, logos, technical information, brand names or the like. The rubber labels are positioned directly on the green tire via an adhesive layer, and then, in a vulcanizing mold, subjected to hot pressing together with the blank. The disadvantage is that an exactly predefined position of the rubber label relative to the tire sidewall engraving cannot be maintained.
DE 10 2009 059 265 A1, which forms the closest prior art, overcomes this disadvantage. The above-cited document discloses a holder and a vulcanizing mold which has this holder, on the sidewall shell of which vulcanizing mold a foil can be exactly positioned, which foil, when the vulcanizing mold is brought together for the hot pressing of the green tire, can be laid onto the sidewall of the green tire. During the vulcanization, a firm connection of the foil to the tire sidewall forms. The sidewall shell does not require any complex means for the arrangement of the foil on the sidewall shell, such as for example separate lateral receiving boundaries for the positioning of the foil which, as a groove in the tire, furthermore entirely or partially delimits the foil. Only at least two spring-mounted pins, which can be recessed into the body of the sidewall shell, are required in order for the foil, which has cutouts corresponding to the pins, to be exactly positioned via the pin heads in the cutouts. Having been securely fixed in a defined manner to the sidewall shell in this way, the foil can be transferred to the tire sidewall. The vulcanizing mold can be used even if no foil is placed into the vulcanizing mold. Aside from scarcely visible imprints of the face surfaces of the pins, no undesired imprints are formed on the tire sidewall.
It has however been found that, during the vulcanization of the green tire, the holder become partially blocked as a result of an ingress of rubber material between pin and sleeve, and thus the pin is no longer adequately movable. This can restrict the functionality of the holder. On the one hand, it could occur that the pin is restricted in terms of its mobility such that this pin does not protrude far enough beyond the sleeve with the force of the spring, such that the foil cannot be placed on the pin head; on the other hand, it could occur that the recessing of the pin into the sleeve is no longer possible, such that undesired imprints would form on the tire.